Oyster industry threatened by climate change

Ocean acidification threatens coastal economies in Oregon, Washington and 13 other states, a report published Monday in the journal Nature Climate Change concludes.

Communities in those 15 states depend on the $1 billion oyster and clam industry.

An acidifying ocean – triggered by an increase in carbon dioxide – kills young mollusks.

"Ocean acidification has already cost the oyster industry in the Pacific Northwest nearly $110 million and jeopardized about 3,200 jobs," said Julie Ekstrom, who was lead author on the study while with the Natural Resources Defense Council and now is at the University of California at Davis.

"This clearly illustrates the vulnerability of communities dependent on shellfish to ocean acidification," said George Waldbusser, a researcher in OSU's College of Earth, Ocean, and Atmospheric Sciences and co-author on the paper.

The analysis identified several "hot zones."

• The Pacific Northwest: Oregon and Washington coasts and estuaries have a "potent combination" of risk factors, including cold waters, upwelling currents that bring corrosive waters closer to the surface, corrosive rivers, and nutrient pollution from land runoff.
• New England: The product ports of Maine and southern New Hampshire feature poorly buffered rivers running into cold New England waters, which are especially enriched with acidifying carbon dioxide.
• Mid-Atlantic: East coast estuaries including Narragansett Bay, Chesapeake Bay, and Long Island Sound have an abundance of nitrogen pollution, which exacerbates ocean acidification in waters that are shellfish-rich.
  
• Gulf of Mexico: Terrebonne and Plaquemines Parishes of Louisiana, and other communities in the region, have shellfish economies based almost solely on oysters, giving this region fewer options for alternative – and possibly more resilient – mollusk fisheries.

The most economically dependent regions – including Massachusetts, New Jersey, Virginia and Louisiana – are the least prepared to respond, the report states, with minimal research and monitoring assets for ocean acidification.

In the Pacific Northwest, though, a robust research effort led by Oregon State University researchers, has helped oyster hatcheries rebound from near-disastrous larval die-offs over the past decade.

The hatcheries now are able to monitor carbon dioxide in the water in real time and add an "antacid" of sodium carbonate when needed, Waldbusser said.

And OSU recently announced plans to launch a Marine Studies Initiative that would help address complex, multidisciplinary problems such as ocean acidification.

"We are still finding ways to increase the adaptive capacity of these communities and industries to cope, and refining our understanding of various species' specific responses to acidification," Waldbusser said. "Ultimately, however, without curbing carbon emissions, we will eventually run out of tools to address the short-term and we will be stuck with a much larger long-term problem."

The analysis was funded through the National Science Foundation's National Socio-Environmental Synthesis Center.

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